“…Later, in celebrated work [13], Christodoulou extended his criterion to the context of the Einstein vacuum equations without symmetry assumptions; in the mean time, important developments have been achieved in that setting [1-3, 29, 30]. Returning to the context of spherically symmetric spacetimes we would like to mention that criteria for the formation of trapped surfaces were also established for solutions of the Einstein-Vlasov equations, in [7], the Einstein-Euler system, in [9], and the Einstein-Maxwell-charged scalar field system, in [6]. Concerning the impact that the formation of a trapped surface has in the global structure of asymptotically flat spherically symmetric spacetimes we refer the reader to the qualitative results in [24,31] and the quantitative results obtained in [4,5,32].…”